I'm only replacing the front and rear seals as the tranny is otherwise in fine shape. But this also requires replacing the front cover gasket as it was destroyed during disassembly.

A couple of questions:

1. The front seal was easy as there's a hole in the cover where I could insert a drift pin to drive out the old seal. But there's nothing similar for the rear seal. What's the best way to remove it and not damage the shaft? I don't have any internal hub pullers.

2. Do I put the gasket on dry or use some kind of sealant on both sides? A PO apparently used some gray RTV silicone as it was all up on the outer races of the main and secondary shaft bearing cages and covered the main bearing snap ring.

Anybody have experience or a reasoned opinion?

Don't lose your countershaft bearing shim. It's very thin, it presses on the countershaft bearing. I think it preloads the bearing so things are right after the aluminum case expands during use. Looks like yours might still be stuck to the cover.

I used non-hardening Hylomar Blue on the front cover gasket. There are other brands available.

This is from the 73 chapter:

Edited August 30Aug 30 by Zed Head

Thanks, @Zed Head , I do know the shim is in the front cover. I'll get some Hylomar Blue.

Any advice on pulling that rear seal? Modified slide hammer?

Edited August 31Aug 31 by Seppi72

I removed a couple of them old school style. No issues. There are a number of other seals that are still available from Nissan. Mainly the shifter shaft seal. Also the detent shift ball bearings and speedometer cog seal. All available through Nissan.

If, @Yarb, by "old school," you mean brute force, then that's the way I ended up going too.

I initially cobbled up three hook arms from coat hanger wire and attached them to my 5-pound slide hammer. They didn't have the tensile strength to overcome the press fit friction between the tranny tail housing and the rear seal.

So, I cut away as much inside rubber from the old seal as I could and then used small cold chisel and hammer to gradually cut a groove down through the metal ring of the seal. Once that was done, I hammered one edge of the cut at an inward angle until the metal bent inwards, relieving the press fit at which point the old seal was removable. There are a few nicks on the aluminum tranny housing edge from doing it this way, but nothing that will affect performance.

Some 3-in-1 oil and a 36 mm socket and hammer then made it easy to install the new seal.

Now, @Zed Head, I have another question. I was easily able to use 800 grit paper to remove residual gasket material and pitting on the front cover. But doing the same on the mating surface inside the bell housing is another matter as I can't get a sanding block down in there. I don't want to use a scraper as I won't have angles to prevent gouging the aluminum. Any recommendations?

All you need is anaerobic gasket maker. Permatex 51813. Coat both sides of the gasket and you’re good to go. Remember that seal goes in from the back side of the plate.

To remove the rear seal, just gently tap a medium-sized flat-blade screwdriver between the shaft and the seal, then pry it out. It’s good to be cautious, but I think you may be overthinking it a little.

Don't tap a screwdriver in between the housing and the seal outer edge. That can damage the housing and create futures leakages.

Oh, and do what Yarb suggested. If you’re replacing these seals because you’re concerned they might leak, then the speedo O-ring, striking rod seal, and O-ring are just as likely to leak if you leave them unchanged. Removing the rear extension housing is not as hard as it seems.

The parts you will need:

Front cover gasket. 32112-08U01

Front seal
30/45 × 8 mm
NOK: AH1679G
Nissan: 32114-Y4000

Rear seal
35/50 × 11 mm
NOK: 400402N
Nissan: 32136-U010A

Striking rod and speedo O-ring
24 × 2.5 mm (ID × CS). 32710-14600

Striking rod inner seal
14/20 × 4.2 mm. 32858-U6702

Speedo pinion seal
10/16 × 4.2 mm. 32709-14600

Reverse checking assembly o-ring (later 5-speed models)
22 × 2.5 mm. No Nissan part number available

Selector checking springs (3 pieces) 32830-20100

Selector return spring 32852-24901

All those parts shouldn't cost more than $30 - $40 max. You can also find a spare parts list in the document section on this site.

https://www.classiczcars.com/files/file/140-fs5w71b-fs5w71c-rebuild-parts-list/?_rid=25317

Spare parts list.

Edited September 1Sep 1 by EuroDat

Thanks, @EuroDat . I have most of those items already and will now look for the others.

Old School Universal techniques Everywhere!!

One more question on this topic: Is the 5-speed slightly longer than the 4-speed? I have three driveshafts and two of them are a little bit shorter than the other and I want to get started on reconditioning whichever one will go into my car.

I used my driveshaft on my conversion and the car was originally an automatic.